Rabbits have been used to induce specific antisera to several different species of basic protein (BP), including homologous (rabbit) BP. With these antisera we have demonstrated several different specific antigenic regions of the BP molecule. Antisera are being used for collaborative experiments on immunocytochemical localization of BP in neonatal rat CNS and in isolated myelin preparations. BIBLIOGRAPHIC REFERENCES: Alvord, E. C., Jr., Shaw, C.-M., Hruby, S., Petersen, R., Hsu, P.C. and Kies, M. W.: Neuro-allergic reactions in primates. In Shiraki, H., Yonezawa, T. and Kuroiwa, Y. (Eds.): The Aetiology and Pathogenesis of the Demyelinating Disease. Tokyo, Japan Science Press, 1976, pp. 203-216. Baker, P. J., Lint, T. F., Siegel, J., Kies, M. W. and Gewurz, H.: Potentiation of C-56 initiated lysis by leucocyte cationic proteins, myelin basic proteins and lysine-rich histones. Immunology 30: 467-473, 1976.